package com.dyz.leetcode._02_string;

public class _13_romanToInt {
    public int romanToInt(String s) {
        char[] chars = s.toCharArray();
        int pre = getValue(chars[0]);
        int sum = 0;
        for(int i =1; i< chars.length; i++){
            int cur = getValue(chars[i]);
            if(pre<cur){
                sum = sum-pre;
            }else {
                sum +=pre;
            }
            pre=cur;
        }
        sum += pre;
        return sum;
    }

    private int getValue(char c){
        switch (c) {
            case 'I': return 1;
            case 'V': return 5;
            case 'X': return 10;
            case 'L': return 50;
            case 'C': return 100;
            case 'D': return 500;
            case 'M': return 1000;
            default:return 0;
        }
    }
}
